The invention relates to an expanded starch confectionery, and more particularly a stick type expanded starch confectionery with a wave-like stereo-configuration on its surface and a process for the manufacture of same.
For manufacturing an expanded starch confectioneries, hitherto, there are a pellet method, wherein a starch raw material is cooked by water steam, kneaded, rolled into a sheet, punched into pieces, dried to obtain pellets, and then roasted or deep-fried to cause expansion thereof, and an extruder method, wherein the starch raw material is fed to an food processing extruder to thermally treat the same, extruded from a die of the extruder to cause expansion thereof, and cut the same.
In case of manufacturing an expanded starch confectionery with a stereo-configuration on its surface, a dough sheet with a certain pattern on its surface can be obtained by the pellet method by using a roll(s) having such a pattern thereon, but pelletizing thereof has been carried out by punching operation and curvature or arcuation shall apt to be occurred during expanding operation, and thus it is quite difficult or impossible to manufacture stick type expanded products, by the pellet method.
According to the extruder method, the starch raw material thermally treated under pressure in the extruder is extruded from a die thereof to cause expansion thereof and thus a stick type expanded product can be obtained, but for giving an intended stereo-pattern to surface thereof, an additional pattern forming step is required to make troublesome the process and increase production cost.
Therefore, it may be fairly be said that a stick type expanded starch confectionery with an intentional and more particularly, a regular stereo-pattern on surface thereof has not been manufactured.
Therefore, an object of the invention is to dissolve said problems in the prior arts, and to provide a stick type expanded starch confectionery with a wave-like stereo-configuration on its surface by the extruder method and a process for the manufacture thereof.
The inventors have energetically studied and investigated for dissolving the problems in the prior arts to finally find that a stick type expanded starch confectionery with the wave-like configuration on its surface can be manufactured by controlling fluidity of a starch dough thermally treated under pressure and to be extruded from a die belonging to an extruder with amounts of water and calcium salt for preparing the dough, and selecting the die having a double stage structure, whereby rotational motion of the dough given by a screw of the extruder is maintained or amplified also near outlet of the die, although such a motion shall be remarkably damped in a conventional food processing extruder.
Therefore, a process for the manufacture of the stick type starch confectionery with a wave-like configuration on surface thereof, according to the invention comprises steps of adding water to cereals or a mixture of the cereals and pulses to mix and homogenize the same, leaving the homogenized mass as it is, for a time, adding a calcium salt and mixing the same to prepare a dough, feeding the dough into an extruder to thermally treat the same, and extruding the cooked dough through a double-staged die which has an outlet-side inner diameter larger than inlet-side one, a gradually enlarging inner diameter in a transitional portion from an ending part of the inlet-side to a beginning part of the outlet-side in linearly or curved line, toward the outlet-side, and a circular cross-section.
In the double-staged die, it is preferable that the inner diameter at inlet-side for the dough is not exceeding 10 mm and that the inner diameter at outlet-side is 2-30 mm and about twice of the inner diameter at inlet-side. A feeding rate of the dough charging into the extruder depends on dough extruding ability of the extruder due to rotational speed of a screw arranged therein.
The stick type expanded starch confectionery according to the invention is that obtained by-such a process and characterized in that a calcium salt contains 0.5-5 parts by weight to 100 parts by weight of cereals or a mixture of the cereals and pulses, as the starch raw materials.
As the cereals, corn grits, wheat flour and rice flour can be exemplified, and soy bean flour, green gram flour and red bean flour can be exemplified, as the pulses. As the calcium salt, egg shell calcium, calcium carbonate and calcium sulfate can be exemplified.
The process according to the invention will now be explained in more detail. In the first place, water of 1-14 parts by weight and more preferably 5-11 parts by weight is added to 100 parts by weight of the starch raw material of cereals or a mixture of cereals and pulses to mix and homogenize the same and to leave it as it is, for a time of 20-60 minutes, so that moisture sufficiently permeates into the starch raw material. Then, a calcium salt, for instance, egg shell calcium of 0.5-5 parts by weight and more preferably 1.4-2.8 parts by weight is added to the homogenized substance to mix the same for preparing a starch dough. A seasoning, for instance, table salt sodium glutaminate or the like may be added until an amount of 30 parts by weight to 100 parts by weight of the starch raw material, as occasion demands.
If the leaving period of time, after added the water is too short and thus the permeation of water into the raw material is not sufficient, a blocking phenomenon shall occur due to contact of the calcium salt to be added later with water, whereby the calcium salt does not homogeneously disperse to make difficult to obtain products with a constant quality and decrease productivity. If the leaving period of time is too long, while, the permeation of water into the raw material proceeds but drying of homogenized of wetty mass of the raw materials shall cause from its surface, which makes difficult to obtain product with a constant quality and decreases productivity, similar to the above.
Thereafter, the starch dough prepared as above is charged into the extruder with double-staged die having inner diameter at outlet-side larger than that at inlet-side and circular cross-section to cook the starch dough under conditions of inner pressure of 50-70 kg/cm2 and temperature of 130-145xc2x0 C. and extrude the cooked starch dough through the die to cause expansion and formation thereof, whereby a desired stick type expanded starch confectionery with a wave-like stereo-configuration on its surface can be obtained.